He said BSF troopers challenged and fired at smugglers on the other side of the barbed wire fence but they managed to escape taking advantage of the darkness and the standing paddy crop while leaving behind the heroin packets.

The seized heroin is said to be valued at Rs.20 crore in the international market.

The BSF has so far seized 258 kg of heroin this year while 322 kg of the contraband material was seized in 2013 in the state.